A double focusing zero dispersion magnetic spectrometer has been constructed having the following properties:The spectrometer consists of two magnets, eachn≅0.25, 110° deflection, 30-in. radius of curvature, bending theparticles in the same sense. For the central momentump0, the useful solid angle&OHgr;0is ∼0.0055 sr with a possibilityof improvement to 0.01 sr. The momentum acceptance&Dgr;pis in excess of ±4% with a useful solid angle &OHgr; of ∼0.0015sr at the 4% points. For a point source and for the solid angles and momentum acceptances given, over 90% of thetrajectories terminate within a circle of 2-in. diameter at the focal plane.